Alas White Owl, the answer is in the archives (here) when she went on a combat date with Thor. The Axe and Armor (well armor of sorts) are deployed by activating a small skull artifact which she apparently keeps hidden within her thick raven locks.

So first of all, DuLapel, yes she is sexy and she knows it. Wiggle Wiggle Axechop to your gonads. That should keep them still.

So as far as where the axe comes from: The truth of the matter is that it's never been revealed where she keeps her axe. DuLapel points out to a previous page where she had her emotion guard transform into her helmet, but that's been seen before. Her wings also transformed into her bat-ish wings at that time. So while I can see why DuLapel thinks that where the axe comes from, it's not actually the case.

The hidden powers of the axe and where it came from were hinted at, but never actually revealed outright.

and Aqua, AF always smiles when she has a chance to inflict some mayhem. Remember, being the Anger Faerie is something of a job for AF. But find a job you love and you'll never work a day in your life :)